An electrically conductive composite coating for anti-icing of insulators and a method for producing the same

Abstract

This application provides an electrothermal conductive composite coating for zoned anti-icing of insulators and its preparation method, relating to the field of high-voltage external insulation disaster prevention technology. The composite coating includes a hydrophobic insulating and thermally conductive layer disposed on the upper surface of the insulator skirt and a composite electrothermal zone disposed on the lower surface of the insulator skirt. The composite electrothermal zone includes an inner semiconductor electrothermal layer and an outer hydrophobic insulating and thermally conductive layer, with the outer hydrophobic insulating and thermally conductive layer connected to the hydrophobic insulating and thermally conductive layer on the upper surface of the insulator skirt. This invention uses the composite electrothermal zone disposed on the lower surface of the insulator skirt as an active heat source and establishes a heat conduction path along the surface of the insulator skirt by means of the hydrophobic thermally conductive zone on the upper surface. When icing occurs, the ice layer connects to form a current loop and efficiently conducts heat to the icing area. At the same time, the superhydrophobic properties of the outer surface reduce the ice crystal nucleation rate and ice layer adhesion, making the ice layer and ice ridges easier to detach, significantly improving the anti-icing performance of the insulator.

Description

Technical Field

[0001] This invention relates to the field of high-voltage external insulation disaster prevention technology, specifically to an electrothermal conductive composite coating for partitioned anti-icing of insulators and its preparation method. Background Technology

[0002] In high-altitude and high-latitude regions, flashover accidents caused by insulator icing have become the primary threat to power grid safety. Icing can reduce the flashover voltage of composite insulators by 60-70% (compared to the dry state), while the effective creepage distance reduction rate caused by ice ridge growth is as high as 45%, which drastically reduces the insulation performance of the insulators.

[0003] In recent years, superhydrophobic coatings, as a typical passive anti-icing method, have been applied to some extent in the field of insulator anti-icing. However, existing superhydrophobic surfaces are prone to losing their hydrophobicity under long-term high humidity, electric field, and mechanical wear environments, making it difficult to maintain long-term anti-icing performance. On the other hand, although electrothermal insulators based on an open-circuit layout introduce an active heat source and can suppress icing to a certain extent, the heat generated is limited by the high thermal resistance characteristics of the insulator skirt substrate (thermal conductivity of approximately 0.2 W / (m·K)), exhibiting an unbalanced thermal field distribution of 'hot at the bottom and cold at the top'. This results in the ice layer on the upper surface not receiving sufficient melting heat flow, while the heat on the lower surface is ineffectively dissipated, severely restricting the energy utilization efficiency of electrothermal anti-icing. Therefore, there is an urgent need for a method to improve the utilization rate of the electrothermal effect by optimizing the heat conduction mechanism while ensuring insulation performance, thereby achieving efficient anti-icing of insulators. Summary of the Invention

[0004] The purpose of this invention is to provide an electrothermal conductive composite coating for partitioned anti-icing of insulators and its preparation method, so as to improve the above-mentioned problems. To achieve the above objective, the technical solution adopted by this invention is as follows:

[0005] In a first aspect, this application provides an electrothermal conductive composite coating for partitioned anti-icing of insulators, including a hydrophobic insulating and thermally conductive layer disposed on the upper surface of the umbrella skirt, and a composite electrothermal zone disposed on the lower surface of the umbrella skirt;

[0006] The composite electrothermal region includes a semiconductor electrothermal layer located in the inner layer and a hydrophobic insulating thermal conductive layer located in the outer layer. The hydrophobic insulating thermal conductive layer in the outer layer is connected to the hydrophobic insulating thermal conductive layer on the upper surface of the umbrella skirt.

[0007] Secondly, this application also provides a method for preparing an electrothermal conductive composite coating for partitioned anti-icing of insulators, comprising:

[0008] Carbon-based conductive filler is dispersed in an organic solvent, and after dispersion, a polymer matrix and a curing agent are added and stirred evenly to obtain a semiconductor electrothermal coating.

[0009] Insulating and thermally conductive fillers and low surface energy modified particles are dispersed in an organic solvent. After dispersion, a polymer matrix and a curing agent are added and stirred evenly to obtain a hydrophobic insulating and thermally conductive coating.

[0010] The semiconductor electrothermal coating is applied to the lower surface of the insulator skirt and then initially cured to form a semiconductor electrothermal layer.

[0011] The hydrophobic insulating and thermally conductive coating is applied to the upper surface of the insulator skirt and the outer surface of the semiconductor electrothermal layer.

[0012] The coated insulators are then subjected to complete curing.

[0013] The beneficial effects of this invention are as follows:

[0014] The electrothermal conductive composite coating for insulator partitioning anti-icing of this invention uses a composite electrothermal zone disposed on the lower surface of the shed as an active heat source, and establishes a heat conduction path along the shed surface with the help of a hydrophobic thermally conductive zone on the upper surface. During icing, the ice layer connects to form a current loop and efficiently conducts heat to the icing area. At the same time, the superhydrophobic properties of the outer surface reduce the ice crystal nucleation rate and ice layer adhesion, making the ice layer and ice ridges easier to detach. Through the electrothermal-hydrophobic composite functional layer forming an anti-icing closed loop of "active heat generation - efficient heat conduction - low adhesion desorption" during the dynamic evolution of icing, the anti-icing performance of the insulator is significantly improved. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the partitioned anti-icing composite coating structure of the composite silicone rubber insulator in an embodiment.

[0017] Symbol explanation: 1-Umbrella skirt; 2-Composite electric heating zone; 3-Hydrophobic insulating and thermally conductive layer. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0019] In this application, numerical ranges are referred to as continuous unless otherwise specified, and include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0020] In high-altitude, high-humidity areas with severe icing due to microclimates, transmission line insulators are highly susceptible to icing under conditions of low temperatures, rime, and frost. Icing can lead to a series of serious problems:

[0021] Ice bridging skirts significantly reduce the flashover voltage of insulators, which can easily trigger ice flashover tripping and cause large-scale power outages.

[0022] Increased icing weight leads to excessive mechanical loads on insulators, fittings, and towers, resulting in breakage and tower collapse accidents.

[0023] When ice melts, it forms a dirty water film, which can easily cause flashover of the ice and lead to a sharp decline in insulation performance.

[0024] Existing methods for heating and melting ice, such as resistance wire heating, short-circuit current melting, and electromagnetic induction heating, can produce a certain degree of ice-melting effect, but they have high heating energy consumption, low heat utilization rate, and the anti-icing effect and energy utilization rate still need to be optimized.

[0025] Example 1:

[0026] See Figure 1 To address the existing technical problems, this embodiment provides an electrothermal conductive composite coating for partitioned anti-icing of insulators, including a hydrophobic insulating and thermally conductive layer 3 disposed on the upper surface of the umbrella skirt 1, and a composite electrothermal zone 2 disposed on the lower surface of the umbrella skirt 1.

[0027] The composite electrothermal zone 2 includes an inner semiconductor electrothermal layer and an outer hydrophobic insulating thermally conductive layer 3. The outer hydrophobic insulating thermally conductive layer 3 is connected to the upper surface of the umbrella skirt 1.

[0028] As an optional implementation, the semiconductor electrothermal layer includes a polymer matrix and a carbon-based conductive filler;

[0029] The hydrophobic insulating and thermally conductive layer 3 comprises a polymer matrix, ceramic filler, and low surface energy modified particles.

[0030] As an optional implementation, the polymer matrix includes either polydimethylsiloxane (PDMS) or room temperature vulcanizing silicone rubber (RTV).

[0031] As an optional implementation, the carbon-based conductive filler includes at least one of graphene, carbon nanotubes, carbon black, and carbon fiber.

[0032] As an optional embodiment, the ceramic filler includes at least one selected from hexagonal boron nitride (h-BN), aluminum nitride (AlN), alumina (Al2O3), and silicon carbide (SiC). Hexagonal boron nitride (h-BN) is preferred.

[0033] As an optional implementation, the low surface energy modified particles include hydrophobically modified nano-fluorinated silica (F-SiO2).

[0034] The hydrophobic insulating and thermally conductive layer 3 has a micro-nano composite rough structure. This structure is constructed with micron-sized sheet-like hexagonal boron nitride (h-BN) as the micro-skeleton and nano-sized fluorinated silicon dioxide (F-SiO2) particles attached to the surface. Utilizing the high in-plane thermal conductivity of sheet-like hexagonal boron nitride, an anisotropic thermal conductive path is constructed inside the coating to guide the heat generated by the semiconductor electrothermal layer to diffuse radially along the surface of the umbrella skirt 1.

[0035] The volume resistivity of the semiconductor electrothermal layer described in this invention is 1.0 × 10⁻⁶. 4 ~1.0×10 7 The thermal conductivity of the hydrophobic insulating and thermally conductive layer 3 is 1.0 to 2.0 W / (m·K), and its electrical insulation strength is not lower than that of the substrate material of the insulator skirt 1; the static water contact angle of the hydrophobic insulating and thermally conductive layer 3 is greater than 150°, and the roll-off angle is less than 10°.

[0036] As an optional implementation, in the semiconductor electrothermal layer, the mass fraction of carbon-based conductive filler is 15-30%, and the mass fraction of polymer matrix is ​​70-85%.

[0037] As an optional implementation, in the hydrophobic insulating and thermally conductive layer 3, the mass ratio of ceramic filler to low surface energy modified particles is (3-5):1, the total mass fraction of ceramic filler and low surface energy modified particles is 35% to 60%, and the mass fraction of polymer matrix is ​​40% to 65%.

[0038] Example 2:

[0039] This embodiment provides a method for preparing an electrothermal conductive composite coating for partitioned anti-icing of insulators, including:

[0040] S1. Substrate pretreatment: Clean the surface of the composite silicone rubber insulator with anhydrous ethanol to remove dust, oil and impurities, and ensure that the umbrella skirt substrate surface is dry before spraying.

[0041] S2. Preparation of Semiconductor Electrothermal Coating: Few-layer graphene powder with a particle size of 2 μm was selected as a carbon-based conductive filler, with a mass fraction of 18%. The carbon-based conductive filler was dispersed in tetrahydrofuran organic solvent and ultrasonically exfoliated for 1 hour. After dispersion treatment, a polymer matrix and curing agent were added, and KH560 coupling agent was added and stirred evenly to obtain the semiconductor electrothermal coating. The mass ratio of the polymer matrix to the curing agent was 10:1, and the polymer matrix was polydimethylsiloxane (PDMS). The volume resistivity of the semiconductor electrothermal coating was 2.7 × 10⁻⁶. 5 Ω·m.

[0042] S3. Preparation of hydrophobic insulating and thermally conductive coating: Insulating and thermally conductive filler and low surface energy hydrophobic modified material are co-dispersed in an organic solvent. After dispersion treatment, a polymer matrix (PDMS) and a curing agent are added, and the mixture is stirred evenly to prepare the hydrophobic insulating and thermally conductive coating. The insulating and thermally conductive filler is selected from hexagonal boron nitride (h-BN) micro powder with a particle size of 2μm, and the low surface energy hydrophobic modified material is selected from fluorinated silica (F-SiO2) nanoparticles with a mass ratio of 4:1. The total mass fraction of the filler is 50%, and the mass fraction of PDMS is 50%. The hydrophobic insulating and thermally conductive coating has a thermal conductivity of 2.0 W / (m·K) and a contact angle of 158°.

[0043] S4. Constructing the inner heat-generating layer: The semiconductor electrothermal coating is applied to the lower surface of the insulator skirt and initially cured to form a semiconductor electrothermal layer.

[0044] S5. Construct an outer hydrophobic and thermally conductive layer: Apply the hydrophobic insulating and thermally conductive coating to the upper surface of the insulator skirt and the outer surface of the semiconductor heating layer; during the coating process, control the hydrophobic insulating and thermally conductive outer layer to completely cover the edge of the semiconductor heating layer, ensuring that the heat generation layer on the lower surface is completely encapsulated.

[0045] S6. Overall curing: Place the coated insulator at 80℃ for 3 hours for complete curing, so that the outer hydrophobic insulating and thermally conductive coating forms a dense interface with the inner layer and the skirt substrate.

[0046] Example 3:

[0047] This embodiment provides a method for preparing an electrothermal conductive composite coating for partitioned anti-icing of insulators, including:

[0048] S1. Substrate pretreatment: Clean the surface of the composite silicone rubber insulator with anhydrous ethanol to remove dust, oil and impurities, and ensure that the umbrella skirt substrate surface is dry before spraying.

[0049] S2. Preparation of Semiconductor Electrothermal Coating: Carbon nanotubes with a particle size of 5 μm were selected as carbon-based conductive fillers, with a mass fraction of 25%. The carbon-based conductive fillers were dispersed in tetrahydrofuran organic solvent and ultrasonically exfoliated for 1 hour. After dispersion treatment, a polymer matrix and curing agent were added, and KH560 coupling agent was added and stirred evenly to obtain the semiconductor electrothermal coating. The mass ratio of the polymer matrix to the curing agent was 9:1, and the polymer matrix was room temperature vulcanizing silicone rubber (RTV). The volume resistivity of the semiconductor electrothermal coating was 8.1 × 10⁻⁶. 4 Ω·m.

[0050] S3. Preparation of hydrophobic insulating and thermally conductive coating: Insulating and thermally conductive filler and low surface energy hydrophobic modifier are co-dispersed in an organic solvent. After dispersion treatment, a polymer matrix (RTV) and curing agent are added, and the mixture is stirred evenly to prepare the hydrophobic insulating and thermally conductive coating. The insulating and thermally conductive filler is selected from alumina (Al2O3) micropowder with a particle size of 5μm, and the low surface energy hydrophobic modifier is selected from fluorinated silica (F-SiO2) nanopowder with a mass ratio of 4:1. The total mass fraction of the filler is 40%, and the mass fraction of the RTV is 60%.

[0051] S4. Constructing the inner heat-generating layer: The semiconductor electrothermal coating is applied to the lower surface of the insulator skirt and initially cured to form a semiconductor electrothermal layer.

[0052] S5. Construct an outer hydrophobic and thermally conductive layer: Apply the hydrophobic insulating and thermally conductive coating to the upper surface of the insulator skirt and the outer surface of the semiconductor heating layer; during the coating process, control the hydrophobic insulating and thermally conductive outer layer to completely cover the edge of the semiconductor heating layer, ensuring that the heat generation layer on the lower surface is completely encapsulated.

[0053] S6. Overall curing: Place the coated insulator at 90℃ for 3 hours for complete curing, so that the outer hydrophobic insulating and thermally conductive coating forms a dense interface with the inner layer and the skirt substrate.

[0054] Example 4:

[0055] This embodiment provides a method for preparing an electrothermal conductive composite coating for partitioned anti-icing of insulators, including:

[0056] S1. Substrate pretreatment: Clean the surface of the composite silicone rubber insulator with anhydrous ethanol to remove dust, oil and impurities, and ensure that the umbrella skirt substrate surface is dry before spraying.

[0057] S2. Preparation of Semiconductor Electrothermal Coating: Carbon black with a particle size of 5 μm was selected as the carbon-based conductive filler, with a mass fraction of 30%. The carbon-based conductive filler was dispersed in tetrahydrofuran organic solvent and ultrasonically exfoliated for 1 hour. After dispersion treatment, a polymer matrix and curing agent were added, and KH560 coupling agent was added and stirred evenly to obtain the semiconductor electrothermal coating. The mass ratio of the polymer matrix to the curing agent was 9:1, and the polymer matrix was room temperature vulcanizing silicone rubber (RTV). The volume resistivity of the semiconductor electrothermal coating was 8.1 × 10⁻⁶. 4 Ω·m.

[0058] S3. Preparation of hydrophobic insulating and thermally conductive coating: Insulating and thermally conductive filler and low surface energy hydrophobic modifier are co-dispersed in an organic solvent. After dispersion treatment, a polymer matrix (RTV) and curing agent are added, and the mixture is stirred evenly to prepare the hydrophobic insulating and thermally conductive coating. The insulating and thermally conductive filler is silicon carbide (SiC) micropowder with a particle size of 1 μm, and the low surface energy hydrophobic modifier is fluorinated silica (F-SiO2) nanopowder with a mass ratio of 5:1. The total mass fraction of the filler is 60%, and the mass fraction of the RTV is 40%.

[0059] S4. Constructing the inner heat-generating layer: The semiconductor electrothermal coating is applied to the lower surface of the insulator skirt and initially cured to form a semiconductor electrothermal layer.

[0060] S5. Construct an outer hydrophobic and thermally conductive layer: Apply the hydrophobic insulating and thermally conductive coating to the upper surface of the insulator skirt and the outer surface of the semiconductor heating layer; during the coating process, control the hydrophobic insulating and thermally conductive outer layer to completely cover the edge of the semiconductor heating layer, ensuring that the heat generation layer on the lower surface is completely encapsulated.

[0061] S6. Overall curing: The coated insulator is placed at 85°C for 4 hours for complete curing, so that the outer hydrophobic insulating and thermally conductive coating forms a dense interface with the inner layer and the skirt substrate.

[0062] Example 5:

[0063] This embodiment provides a method for preparing an electrothermal conductive composite coating for partitioned anti-icing of insulators, including:

[0064] S1. Substrate pretreatment: Clean the surface of the composite silicone rubber insulator with anhydrous ethanol to remove dust, oil and impurities, and ensure that the umbrella skirt substrate surface is dry before spraying.

[0065] S2. Preparation of Semiconductor Electrothermal Coating: Carbon black with a particle size of 5 μm was selected as the carbon-based conductive filler, with a mass fraction of 15%. The carbon-based conductive filler was dispersed in tetrahydrofuran organic solvent and ultrasonically exfoliated for 1.5 hours. The ultrasonic exfoliation time was sufficient to open the interlayer of the sheet-like filler without damaging its lateral dimensions. After dispersion, a polymer matrix and curing agent were added, and KH560 coupling agent was added and stirred evenly to obtain the semiconductor electrothermal coating. The mass ratio of the polymer matrix to the curing agent was 12:1, and the polymer matrix was room temperature vulcanizing silicone rubber (RTV). The volume resistivity of the semiconductor electrothermal coating was 5.5 × 10⁻⁶. 5 Ω·m.

[0066] S3. Preparation of hydrophobic insulating and thermally conductive coating: Insulating and thermally conductive filler and low surface energy hydrophobic modifier are co-dispersed in an organic solvent. After dispersion treatment, a polymer matrix (RTV) and curing agent are added, and the mixture is stirred evenly to prepare the hydrophobic insulating and thermally conductive coating. The insulating and thermally conductive filler is aluminum nitride (AlN) micropowder with a particle size of 6 μm, and the low surface energy hydrophobic modifier is fluorinated silica (F-SiO2) nanopowder with a mass ratio of 3:1. The total mass fraction of the filler is 55%, and the mass fraction of the RTV is 45%.

[0067] S4. Constructing the inner heat-generating layer: The semiconductor electrothermal coating is applied to the lower surface of the insulator skirt and initially cured to form a semiconductor electrothermal layer.

[0068] S5. Construct an outer hydrophobic and thermally conductive layer: Apply the hydrophobic insulating and thermally conductive coating to the upper surface of the insulator skirt and the outer surface of the semiconductor heating layer; during the coating process, control the hydrophobic insulating and thermally conductive outer layer to completely cover the edge of the semiconductor heating layer, ensuring that the heat generation layer on the lower surface is completely encapsulated.

[0069] S6. Overall curing: The coated insulator is placed at 80℃ for 4 hours for complete curing, so that the outer hydrophobic insulating and thermally conductive coating forms a dense interface with the inner layer and the skirt substrate.

[0070] Example 6:

[0071] This embodiment provides a method for preparing an electrothermal conductive composite coating for partitioned anti-icing of insulators, including:

[0072] S1. Substrate pretreatment: Clean the surface of the composite silicone rubber insulator with anhydrous ethanol to remove dust, oil and impurities, and ensure that the umbrella skirt substrate surface is dry before spraying.

[0073] S2. Preparation of Semiconductor Electrothermal Coating: Carbon fibers with a particle size of 3 μm were selected as carbon-based conductive fillers, with a mass fraction of 25%. The carbon-based conductive fillers were dispersed in tetrahydrofuran organic solvent and ultrasonically exfoliated for 1.5 hours. After dispersion treatment, a polymer matrix and curing agent were added, and KH560 coupling agent was added and stirred evenly to obtain the semiconductor electrothermal coating. The mass ratio of the polymer matrix to the curing agent was 10:1, and the polymer matrix was polydimethylsiloxane (PDMS). The volume resistivity of the semiconductor electrothermal coating was 7.1 × 10⁻⁶. 6 Ω·m.

[0074] S3. Preparation of hydrophobic, insulating, and thermally conductive coating: Insulating and thermally conductive fillers and low surface energy hydrophobic modifiers are co-dispersed in an organic solvent. After dispersion treatment, polydimethylsiloxane (PDMS) is added, and the mixture is stirred evenly to prepare the hydrophobic, insulating, and thermally conductive coating. The insulating and thermally conductive filler is selected from hexagonal boron nitride (h-BN) micropowder with a particle size of 4 μm, and the low surface energy hydrophobic modifier is selected from fluorinated silica (F-SiO2) nanopowder with a mass ratio of 3:1. The total mass fraction of the filler is 35%, and the mass fraction of PDMS is 65%.

[0075] S4. Constructing the inner heat-generating layer: The semiconductor electrothermal coating is applied to the lower surface of the insulator skirt and initially cured to form a semiconductor electrothermal layer.

[0076] S5. Construct an outer hydrophobic and thermally conductive layer: Apply the hydrophobic insulating and thermally conductive coating to the upper surface of the insulator skirt and the outer surface of the semiconductor heating layer; during the coating process, control the hydrophobic insulating and thermally conductive outer layer to completely cover the edge of the semiconductor heating layer, ensuring that the heat generation layer on the lower surface is completely encapsulated.

[0077] S6. Overall curing: Place the coated insulator at 85℃ for 3 hours for complete curing, so that the outer hydrophobic insulating and thermally conductive coating forms a dense interface with the inner layer and the skirt substrate.

[0078] This invention reduces heat dissipation caused by poor thermal conductivity of the insulator skirt substrate by constructing a high thermal conductivity surface network, enabling Joule heat to bypass the high thermal resistance substrate and be directionally transported to the ice-accumulation interface. It also utilizes active heat transfer to induce phase change micro-melting at the ice / coating interface, and combines the low ice adhesion characteristics of the superhydrophobic surface to achieve overall ice removal, significantly reducing the anti-icing efficiency ratio. By adopting a composite structure of "inner layer heat generation and outer layer encapsulation", the nonlinear voltage equalization effect of the semiconductor layer is utilized to improve the electric field distribution, and the excellent anti-fouling and anti-icing properties of its hydrophobic, insulating and thermally conductive outer layer are used to synergistically delay the aging process of the insulator skirt substrate, ensuring electrical safety and long-term stability of anti-icing performance throughout the entire life cycle.

[0079] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A heat-conducting composite coating for zoned anti-icing of insulators, characterized in that, It includes a hydrophobic insulating and thermally conductive layer disposed on the upper surface of the umbrella skirt, and a composite electrothermal zone disposed on the lower surface of the umbrella skirt; The composite electrothermal region includes a semiconductor electrothermal layer located in the inner layer and a hydrophobic insulating thermal conductive layer located in the outer layer. The hydrophobic insulating thermal conductive layer in the outer layer is connected to the hydrophobic insulating thermal conductive layer on the upper surface of the umbrella skirt.

2. The electrothermal conductive composite coating for insulator zone anti-icing according to claim 1, characterized in that, The semiconductor electrothermal layer comprises a polymer matrix and a carbon-based conductive filler; The hydrophobic insulating and thermally conductive layer comprises a polymer matrix, ceramic filler, and low surface energy modified particles.

3. The electrothermal conductive composite coating for insulator zone anti-icing according to claim 2, characterized in that, The polymer matrix includes either polydimethylsiloxane or room temperature vulcanized silicone rubber.

4. The electrothermal conductive composite coating for insulator partition anti-icing according to claim 2, characterized in that, The carbon-based conductive filler includes at least one of graphene, carbon nanotubes, carbon black, and carbon fiber.

5. The electrothermal conductive composite coating for insulator partition anti-icing according to claim 2, characterized in that, The ceramic filler includes at least one of hexagonal boron nitride, aluminum nitride, aluminum oxide, and silicon carbide.

6. The electrothermal conductive composite coating for insulator zone anti-icing according to claim 2, characterized in that, The low surface energy modified particles include nano-fluorinated silicon dioxide.

7. The electrothermal conductive composite coating for insulator zone anti-icing according to claim 2, characterized in that, In the semiconductor electrothermal layer, the mass fraction of carbon-based conductive filler is 15%–30%, and the mass fraction of polymer matrix is ​​70%–85%.

8. The electrothermal conductive composite coating for insulator partition anti-icing according to claim 2, characterized in that, In the hydrophobic insulating and thermally conductive layer, the mass ratio of ceramic filler to low surface energy modified particles is (3-5):1, the total mass fraction of ceramic filler and low surface energy modified particles is 35% to 60%, and the mass fraction of polymer matrix is ​​40% to 65%.

9. The method for preparing the electrothermal conductive composite coating for partitioned anti-icing of insulators according to any one of claims 2-8, characterized in that, include: Carbon-based conductive filler is dispersed in an organic solvent, and after dispersion, a polymer matrix and a curing agent are added and stirred evenly to obtain a semiconductor electrothermal coating. Insulating and thermally conductive fillers and low surface energy modified particles are dispersed in an organic solvent. After dispersion, a polymer matrix and a curing agent are added and stirred evenly to obtain a hydrophobic insulating and thermally conductive coating. The semiconductor electrothermal coating is applied to the lower surface of the insulator skirt and then initially cured to form a semiconductor electrothermal layer. The hydrophobic insulating and thermally conductive coating is applied to the upper surface of the insulator skirt and the outer surface of the semiconductor electrothermal layer. The coated insulators are then subjected to complete curing.

10. The method for preparing the electrothermal conductive composite coating for partitioned anti-icing of insulators according to claim 9, characterized in that, The complete curing process includes placing the insulator at 80°C-90°C for 3-4 hours.

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